A spoiler is a bodywork part forming an extension of the roof that is positioned on the rear of a vehicle and that is designed to improve the aerodynamics (at the rear) of the vehicle on which said part is assembled. Spoilers are also used to enhance the esthetic aspects (style) of the vehicle. Spoilers are positioned at and attached to the top rear of the vehicle between the roof and the upper edge of the rear window, on the roof or on the tailgate.
Certain spoilers also have devices for cleaning the rear window.
Conventionally, rain and dirt are usually removed from the rear window using the rear window wiper and the rear window washer. Unfortunately, rear window wipers and rear window washers tend to be fragile, costly and liable to damage. Moreover, rear window wipers and rear window washers are used much less than front windscreen wipers and front windscreen washers.
For this reason, some spoilers are designed to direct a portion of the air flowing from the front to the rear of the vehicle along the upper surface of the roof panel, directly over the rear window. Consequently, dirt (rain, mud, dust, etc.) is blown away from the rear window.
A movable spoiler arranged in a region of a rear edge of the roof above a rear window is known. This spoiler is movable in that the angle between the spoiler and the roof can be adjusted as a function of the weather conditions. Thus, when it is raining, the spoiler is inclined to form an inclined section in which the raised portion is on the upstream side of the flow. This inclined section thus opposes the air flow and orients same onto the rear window via a space formed between the spoiler and the rear window.
Thus, the air flowing from the front to the rear of the vehicle is blocked by the wall of the spoiler before being directed in a substantially opposite direction.
This type of spoiler thus provides a solution that has a very negative effect on the overall aerodynamic performance of the vehicle.
A spoiler that is static in relation to the vehicle including a movable flap is also known, for example from document EP2711254A2. The movable flap projects from the upper surface of the spoiler and the degree of projection (projection height) increases when the speed of the vehicle drops in order to clean the rear window. Conversely, the degree of projection is reduced as the speed increases, to limit the negative aerodynamic effect.
This type of spoiler, despite providing enhanced aerodynamic performance compared to an entirely movable spoiler, nonetheless provides a solution that is disadvantageous in terms of aerodynamic performance. This is especially true because the movable flap, which is under constant pressure, needs to be reinforced and therefore made heavier to withstand such aerodynamic loads.
Thus, the known systems for cleaning rear windows include a member projecting from the surface extending the roof in order to capture the air flowing along the roof and to redirect same onto the rear window. However, these members have a negative effect on the aerodynamics of the vehicle, in particular at high speeds.
Systems that do not have any movable elements are also known. These devices have a permanent through-opening (formed through the thickness Z of the spoiler) opening out above the rear window, this opening being designed to (passively) allow a portion of the air flow coming from the roof towards the rear window to pass through the opening. “Opening” means a channel having an inlet and an outlet in the thickness (Z) of the spoiler. Thus, the air coming from the roof passively enters the inlet of the channel, then flows through the channel, and finally leaves the channel through the outlet thereof, opposite the rear window.
However, such an opening can have a negative effect on the aerodynamics of the vehicle, notably at high speeds, where aerodynamics are optimum with no diversion of the air, since it is often necessary to direct all of the air coming from the roof towards the rear of the vehicle. Furthermore, the diversion of the path of the air caused by the opening causes noise at certain speeds. These acoustic disturbances can cause discomfort to the driver and passengers, as well as to people outside the vehicle. Such noise may indeed cause noise pollution affecting dwellings located near to high-speed roads.